Vista 64 + 4GB + Unlinked = BSOD at any FSB

eVga 680i motherboard
Core 2 Duo E6600 (2.4Ghz)
4x 1GB OCZ DDR2-800

Under Vista 32bit SP1, I have no problems. FSB set to 1467 to give the CPU 3.3Ghz and Memory UNLINKED and set to 825 at 4-4-4-15 timings. Runs great for months. I upgrade to Vista 64bit SP1 and get crashes in games, windows services crashing and often BSODs when resuming from sleep mode. Each and every BSOD is different, from name to stop code. After extensive troubleshooting I have narrowed down the problem to Vista 64bit having an issue with my memory being unlinked from my FSB. Results of various tests:

FSB at 1066, Unlinked, Memory 800 = BSOD
FSB at 1467, Unlinked, Memory 825 = BSOD
FSB at 1200, Linked, Memory 825 = Ok
FSB at 1600, Linked, Memory 800 = Ok
FSB at 1650, Linked, Memory 825 = Ok

Windows Memory Diagnostic and MemTest 86+ for hours never reveal any problems with the memory. Memory voltage is set to 2.1v.

So whats the deal with Unlinked memory from the FSB thats pooching Vista 64? Anyone have even a remote idea?